A study of bacterial deoxysugars is carried out using two complementary approaches: 1. Detailed examination of individual enzymes involved in the biosynthesis of 6-deoxyhexoses. a. Thymidine diphosphoglucose-4,6-hydrolase, the enzymes initiating 6-deoxyhexose biosynthesis will be studied to increase our understanding of structure and function for "half-site" enzymes. The problem will be explored by: (1) specific chemical modifications of the enzyme protein; (2) studies concerning the process of enzyme-subunit association and dissociation; and (3) kinetic analysis with synthetic substrate and coenzyme analogues and studies on specific enzyme inhibitors. b. Comparative studies will be performed on UDP-galactose-4-epimerase, another "half-site" enzyme with analogous properties to TDPG-4,6-hydrolase. c. TDP-L-rhamnose dehydrogenase and TDP-6-deoxy-L-talose-dehydrogenase will be purified and characterized. Studies using synthetic substrate and coenzyme analogues will be performed. 2. In a synchronized bacterial culture, the levels of enzymes involved in deoxyhexosebiosynthesis will be correlated to 6-deoxyhexose incorporation into cell wall lipopolysaccharide, as well as to cell surface related phenomena as immuno response or agglutination inhibition. It is the objective of these studies to find experimental conditions to interfere with deoxysugar biosynthesis resulting in altered cell surface properties.